1. Technical Field
The present invention relates to liquid ejecting heads, such as ink jet recording heads, and to liquid ejecting apparatuses. In particular, the invention relates to a liquid ejecting head that includes a nozzle forming member in which a plurality of nozzles are provided in rows; a pressure generating unit including a pressure generator that causes pressure fluctuations in a pressure chamber; a communication member in which an empty liquid chamber portion that is to be a portion of a common liquid chamber, and a supply-side communication path that allows communication between the empty liquid chamber portion and the pressure chamber are formed; and a case member to which the communication member to which the nozzle forming member and the pressure generating unit are bonded is fixed, and to a liquid ejecting apparatus.
2. Related Art
A liquid ejecting apparatus is an apparatus that includes a liquid ejecting head and that ejects various types of liquid from the liquid ejecting head. An example of liquid ejecting apparatuses is an image recording apparatus such as an ink jet printer or an ink jet plotter. In recent years, taking advantage of being able to make a small amount of liquid accurately land at a predetermined location, liquid ejecting apparatuses have also been applied to various manufacturing apparatuses. For example, liquid ejecting apparatuses have been applied to display manufacturing apparatuses that manufacture color filters for liquid crystal displays or the like, electrode forming apparatuses that form electrodes for organic electro luminescence (EL) displays, field emission displays (FED) or the like, and chip manufacturing apparatuses that manufacture biochips. A recording head for an image recording apparatus ejects liquid ink. A color material ejecting head for a display manufacturing apparatus ejects liquid solutions of Red (R), Green (G), and Blue (B) color materials. An electrode material ejecting head for an electrode forming apparatus ejects a liquid electrode material. A living organic material ejecting head for a chip manufacturing apparatus ejects a liquid solution of a living organic material.
Some of this type of liquid ejecting head include a nozzle plate in which a plurality of nozzles are formed; a flow path forming substrate in which individual flow paths including pressure chambers that communicate with the respective nozzles, and an empty portion that is to be a portion of a common liquid chamber (also called as a reservoir or a manifold) in which a liquid common to each of the pressure chambers is stored are formed; a plurality of piezoelectric elements (a type of pressure generator) that are provided so as to correspond to the respective pressure chambers; and a common liquid chamber forming substrate in which an empty common liquid chamber portion that is to be a common liquid chamber in which the liquid common to each of the pressure chambers is to be stored is formed (see, for example, JP-A-2005-219243). In this configuration, a silicon single-crystal substrate (a type of crystalline substrate) is employed as a material of the nozzle plate or the flow path forming substrate because a flow path or the like can be formed with a high degree of precision by using an etching process. However, such a silicon single-crystal substrate is costly compared to a substrate made of synthetic resin or the like. In particular, the flow path forming substrate in which the pressure chambers are formed is fabricated by forming a plurality of flow path forming substrates on a silicon single-crystal wafer and then dividing the wafer. Therefore, it is desirable to increase the number of flow path forming substrates to be obtained by further reducing the size of the flow path forming substrate in order to achieve cost reduction.
Specifically, a configuration in which the flow path forming substrate is reduced in size by not providing the empty portion which is to be a portion of the common liquid chamber in the above-described flow path forming substrate has also been proposed.
FIGS. 7A and 7B are schematic diagrams showing an exemplary configuration of the flow path forming substrate and the like that has been reduced in size. FIG. 7A is a cross-sectional view of an essential portion of the configuration, and FIG. 7B is a plan view of the same. Note that a direction perpendicular to the view of FIG. 7A and a vertical direction in FIG. 7B are a nozzle row direction. In this exemplary configuration, a flow path forming substrate 55 in which a pressure chamber 31 is formed, a nozzle plate 57 in which a nozzle 27 is arranged, a communication substrate 59 in which a nozzle communication path 36 that allows communication between the pressure chamber 31 and the nozzle 27 is formed, and an actuator unit 64 that is provided with a piezoelectric element 62 are stacked on top of one another so as to form a head main body portion 54. In this configuration, common liquid chambers 61 are partitioned from one another and formed at a side of the head main body portion 54 by another member (in this case, a case member 65) that is made of a material other than a silicon single-crystal.
In the above-described configuration, for example, when a plurality of common liquid chambers 61 are provided for one nozzle row along the nozzle row direction in a state of being independent of one another, that is, when one common liquid chamber which is provided for one nozzle row is divided into a plurality of common liquid chambers 61, side surfaces of partition walls 66 that partition the adjacent common liquid chambers 61 from one another need to be bonded to a side surface of the head main body portion 54 using an adhesive (an area X in FIG. 7B). However, a sufficient bonded area in this portion cannot be obtained, and the side surface of the head main body portion 54 which is formed of a plurality of component members stacked on top of one another is uneven and thus a sufficient amount of adhesive cannot be poured into this portion. Therefore, ink leaks out from the bonded portion between the adjacent common liquid chambers 61.